Let's take your previous example: the blacksmith wizard. You wanted him to be smart enough to fulfill the role of the party wizard, so gave him Int 16 (after racial), but wanted him to have enough strength to justify his smithing background, so Str 14. So far, so good.
Then you were trying to decide whether he is sociable, OR whether he is perceptive/agile/tough. You cannot have 'what you want' if 'what you want' is all three! That concept cannot be realised through point-buy.
Which is why it's misleading to claim that point-buy lets players realise the concept that they want. Point-buy only lets you realise the pre-conceived idea if that idea adds up to exactly 27 point; a fairly small proportion of all possible PCs with stats in the 3-18 range and the concepts that match them.
It is true that one of the advantages of point-buy is that it allows you to conceive a PC ahead of time and know that it will be legal in the game. Since rolling has you conceive your PC after rolling the stats, which is objectively no better or worse then concept first, then it's not an appropriate criticism that rolling doesn't let you do what you're not supposed to do with it!
If 'rolling mean I can't use my pre-conceived PC' were a valid, objective criticism of point-buy, then 'since the DM's character creation method means that I have to generate scores before I conceive my PC' is a valid criticism of pre-conceived PCs. If rolling for stats is part of the game, then conceiving your PC after rolling is not a bug, it's a feature. It's how the game is played and how it has always been played by me*.
Point-buy is a comparatively recent thing, compared to rolling your stats. It has its own advantages and disadvantages over rolling. It's advantage of pre-conception is opposed by its disadvantage of those concepts being limited to exactly 27 points, instead of a host of new concepts, impossible for point-buy to emulate, open up nearly every single time you roll up a PC!
Let's say that you can have any meal you want....as long as it adds up to exactly 1000 calories. Sure, there are many, many meals you can have, but think of all the meals you cannot have, that you could have if instead of a calorie total you could eat whatever was in the market that day.
* Please don't speak for everyone. I also don't see what rules written (or not written) twenty some odd years ago have to do with the current discussion. Not that it matters and I don't pretend to speak for anyone else but I've been using some variation of point buy since the 80s.
Back to the discussion. We both agree that I can't write up Superman.
But stronger or more charismatic than average is anything more than an 11. Or maybe I start (heaven forbid) with less than a 16 intelligence. Many of my characters don't have optimized stats. Yet again, you are the one getting hung up on numbers.
The rules give me a way of implementing the vision of my character. The rules are there as a means to facilitate that vision but also put boundaries on our characters. That's true with whatever system you use.
If I (and my group) want multiple high all-around stats all we have to do is discuss it with the DM and set the point buy higher. Maybe use the point buy options from a previous edition so I can buy an 18. Done.